90 kg of potatoes are sorted into 3 sizes: large, medium and small. The ratio by mass of the large to medium to small potatoes is 10 : 4 : 1. There are
23 as many large potatoes as medium potatoes. There are
12 as many small potatoes as large potatoes. There are 2 large potatoes per kilogram. Find the total number of small and medium potatoes.
Mass of potatoes |
Large |
Medium |
Small |
Total |
10 u |
4 u |
1 u |
90 kg |
Number of potatoes |
Large |
Medium |
Small |
2 |
3 |
|
2 |
|
1 |
2 p |
3 p |
1 p |
Total mass of potatoes
= 10 u + 4 u + 1 u
= 15 u
15 u = 90
1 u = 90 ÷ 15 = 6
Mass of large potatoes
= 10 u
= 10 x 6
= 60 kg
The number of large potatoes is repeated.
Total number of large potatoes
= 60 x 2
= 120
2 p = 120
1 p = 120 ÷ 2 = 60
Total number of small and medium potatoes
= 3 p + 1 p
= 4 p
= 4 x 60
= 240
Answer(s): 240